Electronic circuit with reverberation effect and improved output controllability
First Claim
1. An electronic circuit for adding reverberation effects to an audio signal produced from an external high impedance source and passing the reverberated audio signal at a predetermined impedance for input into an external sound device, said electronic circuit comprising, in combination:
- a pre-amplifier/driver circuit having a first operational amplifier coupled to a second operational amplifier, each operational amplifier having inverting and non-inverting inputs and an output, each of said outputs comprising a negative feedback loop coupled to said inverting input and shunted to ground for setting a predetermined gain at each of said outputs, said non-inverting input of first operational amplifier having an input jack for receiving therethrough the audio signal produced from the external high impedance source;
a spring reverberation device having an input coupled to said output of second operational amplifier and an output for passage of a reverberated, low impedance signal;
a recovery amplifier circuit comprising a single operational amplifier having an inverting input for receiving the reverberated, low impedance signal and a non-inverting input shunted to ground and an output comprising a negative feedback loop coupled to said inverting input for setting the reverberated, low impedance signal at a predetermined gain and impedance for input into the external sound device; and
a power supply circuit having means for switching between a dc voltage source and an ac voltage source most suitable for powering said first and second and single operational amplifiers.
0 Assignments
0 Petitions
Accused Products
Abstract
An electronic circuit for adding the effects of reverberation to a high impedance signal produced from an external audio source such as a guitar pickup or a high impedance microphone. The electronic circuit comprises a reverberation effects circuit having pre-amplifier/driver and recovery amplifier sections and a spring reverberation device coupled thereinbetween and a reverberation effects bypass at the circuit'"'"'s input, prior to switchably passing the audio signal into an input of the pre-amplifier/driver section which comprises a low impedance, high current output for input into the spring reverberation device having an output for passing a low impedance signal to the recovery amplifier section, which suitably serves in increasing the impedance of the signal to a predetermined level acceptable for input into an external sound device such as an amplifier having channel inputs and audio control capabilities, and a power supply circuit having means for switching between a dc voltage source and an ac voltage source and supplying ±9 volts to integrated circuits (ICs) included in the pre-amplifier/driver and recovery amplifier sections of the reverberation effects circuit.
166 Citations
20 Claims
-
1. An electronic circuit for adding reverberation effects to an audio signal produced from an external high impedance source and passing the reverberated audio signal at a predetermined impedance for input into an external sound device, said electronic circuit comprising, in combination:
-
a pre-amplifier/driver circuit having a first operational amplifier coupled to a second operational amplifier, each operational amplifier having inverting and non-inverting inputs and an output, each of said outputs comprising a negative feedback loop coupled to said inverting input and shunted to ground for setting a predetermined gain at each of said outputs, said non-inverting input of first operational amplifier having an input jack for receiving therethrough the audio signal produced from the external high impedance source;
a spring reverberation device having an input coupled to said output of second operational amplifier and an output for passage of a reverberated, low impedance signal;
a recovery amplifier circuit comprising a single operational amplifier having an inverting input for receiving the reverberated, low impedance signal and a non-inverting input shunted to ground and an output comprising a negative feedback loop coupled to said inverting input for setting the reverberated, low impedance signal at a predetermined gain and impedance for input into the external sound device; and
a power supply circuit having means for switching between a dc voltage source and an ac voltage source most suitable for powering said first and second and single operational amplifiers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for adding reverberation effects to an audio signal produced from an external high impedance device and passing the reverberated audio signal to an external sound device at a predetermined impedance, said method comprising the steps of:
-
sending the audio signal into an non-inverting input of a first operational amplifier having an inverting input shunted to ground and an output comprising a negative feedback loop coupled to said inverting input for setting said output at a predetermined gain and impedance prior to being passed into a non-inverting input of a second operational amplifier having an inverting input shunted to ground and a low impedance, high current output for input into a spring reverberation device having an output for passing therethrough a reverberated, low impedance signal, said negative feedback loop of first operational amplifier comprising a 50K linear potentiometer having variable resistive capacity to variably adjust gain of the audio signal and establish low impedance at said output of first operational amplifier;
passing the reverberated, low impedance signal into an inverting input of a single operational amplifier having a non-inverting input shunted to ground and an output having a negative feedback loop coupled to said inverting input, said negative feedback loop of single operational amplifier comprising a 100K linear potentiometer having variable resistive capacity to variably adjust the audio signal'"'"'s gain and establish a low impedance at said output of single operational amplifier prior to being fed into the external sound device; and
supplying power from an external source to a power supply circuit having means for switching between a dc voltage source and an ac voltage source most suitable for powering said first and second and single operational amplifiers. - View Dependent Claims (12, 13, 14, 15)
-
-
16. An electronic circuit for adding reverberation effects to an audio signal produced from an external high impedance source and passing the reverberated audio signal at a predetermined impedance for input into an external sound device, said electronic circuit comprising, in combination:
-
a first operational amplifier having inverting and non-inverting inputs and an output comprising a negative feedback loop coupled to said inverting input and shunted to ground, said negative feedback loop of first operational amplifier comprising a 50K linear potentiometer having variable resistive capacity to variably adjust the audio signal'"'"'s gain and impedance at said output of first operational amplifier, said non-inverting input of first operational amplifier having an input jack for receiving therethrough the audio signal produced from the external high impedance source, said input jack comprising a reverberation effects bypass for maintaining the integrity and impedance of the audio signal produced by the external high impedance source for direct input into the external sound device;
a second operational amplifier having inverting and non-inverting inputs and an output comprising a negative feedback loop coupled to said inverting input and shunted to ground, said output of first operational amplifier being coupled to said non-inverting input of second operational amplifier having a filter coupled therebefore for blocking passage of dc signals while allowing passage of the audio signal into said second operational amplifier, said negative feedback loop of second operational amplifier comprising a resistor/capacitor arrangement for stabilizing said feedback loop and restoring phase margin to said second operational amplifier;
a spring reverberation device having an input for accepting a low impedance, high current signal from said output of second operational amplifier and an output for passing therethrough a reverberated, low impedance signal;
a single operational amplifier having an inverting input for receiving the reverberated, low impedance signal and a non-inverting input shunted to ground and an output comprising a negative feedback loop coupled to said inverting input, said negative feedback loop of single operational amplifier comprising a 100K linear potentiometer having variable resistive capacity to variably adjust the audio signal'"'"'s gain and establish a low impedance at said output of single operational amplifier prior to being fed into the external sound device; and
a power supply circuit having a transformer for lowering voltage from an outside voltage source from 120 volts ac to 12 volts ac prior to passing into a rectifying portion for converting the voltage source from ac to dc, said power supply circuit comprising a pair of adjustable voltage regulators operably establishing power outputs of ±
9 volts for input into a relay having switching capabilities with a pair of 9 volt batteries coupled thereto and an output coupled to said first and second and single operational amplifiers. - View Dependent Claims (17, 18, 19, 20)
-
Specification